Youtube-dl is a free and open source command line video download tools that can be used to download video from Youtube and other websites like, Facebook, Dailymotion, Google Video, Yahoo and much more. In this tutorial, we will learn how to install and use Youtube-dl on Ubuntu 16.04. We will also learn how to download Youtube video in different quality and formats.Install and Use YouTube-DL on Ubuntu 16.04
Source: HowtoForge Linux Tutorials